Hi,
There are various things that can cause that. Sometimes trying again will work, as odd as that sounds.

I have also heard that if you’ve almost exceeded your allowed disk space, that can happen. You could check how much space you’re using in your hosting account, and how much you’re allowed to have. If you’ve maxed out your space, you’d need to delete some files or upgrade your hosting account.

Finally, you could try manually downloading the update from my.studiopress.com (be sure you’re logged in), unzip the archive to your computer, and then FTP the files to your server.